13.16. Fractal Explorer
| 13. Rendering Filters |

### 13.16. Fractal Explorer

#### 13.16.1. Overview

Figuur 16.317. Example for the Fractal Explorer filter

Filter “Fractal Explorer” applied

With this filter, you can create fractals and multicolored pictures verging to chaos. Unlike the IFS Fractal filter, with which you can fix the fractal structure precisely, this filter lets you perform fractals simply.

#### 13.16.2. Starting filter

You can find this filter through Filters → Render → Fractal Explorer.

#### 13.16.3. Options

Figuur 16.318. “Parameters” options for Fractal Explorer filter

Realtime preview

  Uncheck the Real time preview only if your computer is slow. In this case, you can update preview by clicking on the Redraw button.

  By clicking-dragging mouse pointer on preview, you can draw a rectangle delimiting an area which will be zoomed.

Zoom

  You have there some options to zoom in or zoom out. The Undo allows you to return to previous state, before zooming. The Redo allows you to reestablish the zoom you had undone, without having to re-create it with the zoom-in button.

Parameters tab

  This tab contains some options to set fractal calculation and select fractal type.

  Fractal Parameters

    here, you have sliders and input boxes to set fractal spreading, repetition and aspect.

    XMIN; XMAX; YMIN; YMAX

      You can set fractal spreading between a MINimum and a MAXimum, in the horizontal (X) and/or vertical (Y) directions. Values are from -3.0 to 3.0.

    ITER

      With this parameter, you can set fractal iteration, repetition and so detail. Values are from 0.0 to 1000.0

    CX; CY

      With these parameters, you can change fractal aspect, in the horizontal (X) and/or vertical (Y) directions, except for Mandelbrot and Sierpinski types.

    Open; Reset; Save

      With these three buttons, you can save your work with all its parameters, open a previously saved fractal, or return to the initial state before all modifications.

  Fractal type

    You can choose what fractal type will be, for instance Mandelbrot, Julia, Barnsley or Sierpinski.

Colors tab

  Figuur 16.319. Color tab options

  This tab contains options for fractal color setting.

  Color number

    This slider and its input boxes allow you to set the number of colors for the fractal, between 2 and 8192. A palette of these colors is displayed at the bottom of the tab. Actually, that's a gradient between colors in fractal: you can change colors with “Color intensity ” and “Color function ” options. Fractal colors don't depend on colors of the original image (you can use a white image for fractals as well).

  Use loglog-smoothing

    If this option is checked, the band effect is smoothed.

    Figuur 16.320. Loglog smoothing example

  Color density

    These three sliders and their text-boxes let you set the color intensity in the three Red, Green and Blue color channels. Values vary from 0.0 to 1.0.

  Color function

    For the Red, Green and Blue color channels, you can select how color will be treated:

    - Sinus: Color variations will be modulated according to the sinus function.

    - Cosinus: Color densities will vary according to cosinus function.

    - None: Color densities will vary linearly.

    - Inversion: if you check this option, function values will be inverted.

  Color Mode

    These options allow you to set where color values must be taken from.

    - As specified above: Color values will be taken from the Color density options.

    - Apply active gradient to final image : used colors will be that of active gradient. You should be able to select another gradient by clicking on the gradient source button.

Fractals tab

  Figuur 16.321. “Fractal tab” options

  This tab contains a big list of fractals with their parameters, that you can use as a model: only click on the wanted one.

  The Refresh allows you to update the list if you have saved your work, without needing to re-start GIMP. You can delete the selected fractal from the list by clicking on the Delete.

13.15. Circuit |  | 13.17. Gfig